1. Field of the Invention
The invention relates to an abatement system for ClF.sub.3 containing exhaust gases. It relates more particularly to a process for the abatement of a ClF.sub.x containing gas such as an exhaust gas from a reactor.
2. Description of the Related Art
ClF.sub.3 gas has been widely used recently as a cleaning gas for the CVD reactors because of its high reactivity without the aid of a plasma or high thermal energy. However, the exhaust gas from the reactor after the cleaning of the same, contains various cleaning products and byproducts such as ClF, ClF.sub.2, HF, Cl.sub.2 in addition to ClF.sub.3.
It is well known in the art to use sodalime to remove those toxic compounds from the exhaust gas of a CVD reactor by chemisorption.
It is also well known by the man skilled in the art to use zeolites to adsorb toxic compounds by physisorption from the exhaust gas flowing out of these CVD reactors. Also, scrubbing with an alkaline solution is a widely known method for abatement of toxic compounds in these exhaust gases.
However, the problem with these conventional methods is their inability to totally abate those toxic compounds. The reason is essentially because of their poor efficiency and the generation of secondary toxic compounds by the reaction between the exhausted components and the adsorbent material. Such byproducts include as referred to hereabove, ClF, ClF.sub.2, HF and Cl.sub.2.
There is thus still a need for a system and method to substantially completely abate toxic compounds in the exhaust gases after cleaning a reactor with a ClF.sub.x gas or gas mixture.